As a method of forming a fine concavo-convex structure on a surface of an optical article, a method is performed in which an elongated substrate is arranged on the circumference of a roll-shaped mold, an active energy ray-curable resin composition is filled between the roll-shaped mold and the substrate, the active energy ray-curable resin composition is cured by irradiation of the active energy ray through the substrate, and the cured resin layer and the substrate are separated from the roll-shaped mold, thereby manufacturing a molded body in a continuous manner.
The molded body thus continuously manufactured may be cut or punched into a predetermined shape according to a product specification to be used, in some cases. However, the manufactured molded body may include a defect portion not satisfying required characteristics in some cases. In order to cut or punch the molded body into a predetermined shape while avoiding such a defect portion, generally, marking is carried out on the molded body such that a defect portion can be easily identified and removed.
As a method of marking a defect portion on the molded body, a method of performing marking directly on a film or a method of performing marking by forming a mark on a mold and then transferring the mark onto the molded body is exemplified.
Patent Document 1 discloses a defect marking apparatus capable of directly marking a defect portion on a sheet-shaped product with a pen. Further, Patent Document 2 discloses a defect marking method in which a flaw for marking is made on both end of the defect portion in the width direction that is in the vicinity of the defect portion of the sheet-shaped product.
Further, a method for specifying a defect portion on a mold is performed in which, in order to specify a position on the mold corresponding to the defect portion transferred onto the molded body, a flaw is made in the vicinity of a roll-shaped mold in advance to perform marking and positions of the defect portion and the marking are compared to each other. Patent Document 3 discloses a method of performing marking on an end of a mold and then transferring the marking with a pitch corresponding to the outer circumference of the mold onto the film. Patent Documents 4 and 5 disclose a method of inspecting a manufactured plate or film.